Testing system



TESTING SYSTEM Filed Dec. 18. 1922 lU, Q E a V) UJ D:

I Lb y i wife/722%' Patented Sept. Y7, 192.6.

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` TESTING SYSTEM.

amara ma member 18,1922! Serial romaine.

To attain the .object ofthe invention, `avv selector switch or aftest' distributor having only four inovable'termi-nals. or brushes is employed for extending connections trom the testdesk to connector switches or testconnectors having access;tothe-subscribers lines. The impulses: ttor `setting' )the connector switches are transmitted andithe connector switch isheldy actuated `after itissetover a common circuit which includes oneot the movable terminals ot the selector switch. :The

M movable terminal, over which the impuls-es are tnansmittedfand thegconnector is held, is also employed inltestingthe Connector switch for .a busy,r or idle condition. Ar relay ,at the selector switchvo '-erates. if the selected connector rswitch isid e to disconnect the test 'de-vicesor" ther selector switch from the connector andto connect the impulsesvand holding circuit thereto. y

'It isbel'eved that the .above and other features ofthe invention .will be betterunderstoo'd from -a detailed description of'operation when considere-'d in connectionwith the drawingwhichshows one.r embodimentl of the' invention.

Only such matter-as is embodied in the present invention showninmhe drawing. The apparatus attheleft o1c the dotted line O--O` is located at thetesting operators position. The conductors 90 and 91 Vmay extend to any desired testing circuit. D represents substation apparatusot the Well known type ot a lineterminating in a machine switching central ofiice. For extend ing th e test cireuitto the subscribersstation l), a test vdistribi-itor TD and aitest ,conhector TC are Vshown-to the `right of the dotted line O'-GI fThe apparatus at lthe 'is shown.

right ofthe dotted line Q-O Amay be inthe same oiiice as the ytestingcircuits or in a distant central otlice. lF or connecting vthe apparatus at the testing` operators positionV to theautonlatc switches, a trunk circuit comprising the conductors 84; to S7,` inclusive, For connecting the apparatus `at the-testing operators position tothe trunk circuit, manuallycontroll-ed switches S0 to 83 inclusive are shown. `Theseswitches may 4be of any well known type of manual switch as, torexample, aley or a plugfa'nd jack.

-lVe will now assume `that the testing operator has kactuated the manual switches 80 to inclusive, thereby connecting the key 35 Landthe dial 2O tothe test distributor TD. Connection of the dial 2O to the test distifbutorcauses lthe operation of: relay 10 over a circuit extending from ground, through i the Vri, J;ht-handnormal contacts of key 60, contacts of key l67 ,contact 68 of dial 20, outer rightehand normal contact of relay 27, Winding of relay lOand lett-hand normal contacts o' key 60y to grounded battery. Relay 11 and polarized' relay 12 do not operate .at this-time ydue to the shunt .around their winding through the outer contacts oit relay Relay 10 in operating, completes an yobvious circuit for .slow-tofrelease relay digit,- No. 3 for example, whereuponhe circuit for relay y10 ,willvbeopened three times at contactGSo dial 2O causing three deenergizations of saidfrelay 10. At the iirst deenergization of relaylO, a circuit is completed for relay 1.4 `and primary magnet 1,6 over apath ext-ending .from ground, through the lower normal.'contactsotrelay 10, lower normal contacts ot' relay 11, lower alternate contacts `ot `slow-to-release relay 'Theftesting operator then dials-the rsty The off-normal contacts 65 are also closed at this time to prepare a circuit for release magnet 15. At the second and third dcenergizations ot relay 10, a circuit is completed tor the primary magnet 16 over a path extending from ground, through the normal contacts ot relay 1U, low-er normal contacts ot relay 11, lower alternate contacts of relay 13, contacts 19 ot oit-normal switch 22, alternate contacts ot relay 14, winding of relay 14 and winding or' magnet 16 to grounded battery. Relay 14 being of the slow to release type does not retract its .armature during the intervals between the impulses ot a series. Due to the closures or" the circuit et magnet 16, the brushes ot the switch TD are advanced to the third group of terminals in the bank. After the cessation of the irst series of impulses, relays 1() and 13 remain energized but relay 14 deenergizes due to the opening ot the its circuit at the normal contacts ot relay 10.

When the testing operator dials the next digit, for example llo. 4, the relay will be deenergized tour times and transmit tour impulses over a. circuitwhich may be traced` from ground, through the normal contacts ot relay 10, lower normal contacts ot relay 11, lower alternate contacts ot relay 13, contacts 19 of oit-normal switch 22, normal contacts ot relay 14, and thence in parallel, one path extending through the lett-hand contacts ot' relay 27, winding of relay 26 and winding ot secondary magnet 25 to grounded battery, and the other path extending through the outer right-hand normal contacts of relay 28, normal contacts ot magnet and lower winding of relay 29 to grounded battery. The secondary magnet will be operated four times over this circuit and will move the brushes of the switch TD in their secondary movement into engagement with the terminals leading to the selected test connector TC. Relay 26 is operated in the circuit traced for magnet 25 in response to the transmission of the iirst impulse to nagnet 25. Relay 29, which is ot the slowto-release type, operates at the first deenergization ot relay 10 and remains operated during the secondary movement of the brushes ot switch TD so that relay 30 will not be connected across the brushes and 41 at this time. Relay 26 is et the slow-torelease type and does not retract its armatures during the sending of a series ot' impulses. Relay 26 in operating, completes a circuit :for relay 27 over a path extending from grounded battery, through the winding of relay 27, inner right-hand contacts oi relay 26 and upper contacts of relay 18 to ground. Relay 27, in operating, locks over a path -extending from grounded battery, through the winding and inner right-hand contacts of relay 27, and upper contacts ot relay 13 to ground. Relay 27, in operating,

opens at its outer right-hand contacts, the shunt circuit around relays 11 and 12, but since relay 26 operates before relay 27, a substitute shunt circuit is established around the windings of relays 11 and 12 through the outer right-hand contacts of relay 26. This shunt circuit is maintained as long as slow to release relay 26 remains energized. Relay 26 deenergizes shortly after the brushes 40 to 43 inclusive ot switch TD have been moved in their secondary movement.

It the selected test connector TC is busy, ground will be present at the test terminal 47 and relay 28 will be operated before the slow to release relay 26 can retract its armatures. The circuit for operating relay 28 can be traced trom grounded battery, through the winding of relay 28, intermediate right-hand contacts of relay 27, contact 69 of relay 26, brush 43 and thence to ground on terminal 47. rEhe ground on terminal 47 may be steady, due to the previous selection of connector TC by another test distributor, or intermittent, due to transmission of impulses, thereover. In either ot these cases, relay 28 operates. Relay 28 in operating, locks over a path extending from grounded battery, through the winding o1" relay 28, intermediate right-hand contacts. ot relay 27 and thence to ground at terminal 47 through contacts 69 ot relay 26 as long as relay 26 is operated, and to ground through contacts 70 of relay 2", inner righthand contacts et relay 28 and upper contacts of relay 13 to ground as soon as relay 26 retracts its armatures. Relay 28, in attracting its lett-hand armature, opens the impulse circuit for the test connector so that a further actuation ot' the dial will not aiiect a previous connection to the test connector. Relay 28, in attracting its outer right-hand armature, completes a holding circuit for relayl 29 through the normal contacts of magnet 15 and the low r winding of relay 29. Relay 29 completes a circuit for relay 30 over a path extending trom grounded battery, through interrupter 31, inner alt-ernate contacts ot relay 29, lower normal contacts ot key 85, winding' oil relay 30, upper normal contacts et key 35, outer alternate contacts ot relay 29 to ground. Relay 30 is intermittently operated in this circuit and causes the flashing oit lamp over an obvious circuit as soon as the dial returns to normal and closes ott-normal ,contact 66. The flashing ott this lamp indicates to the operator that the selected test connector is busy.

It the selected test connector is idle. relay 26 releases as soon as the secondary impulses have been delivered but relay 28 will not be operated due to the absence ot ground at the test terminal 47. Due to the release of relay 26, the short circuit is removed trom relays 11 and 12 and said relay 11 operates in Cit f Winding otrelay 52 and Windingfoilmagnet' the impulses oit relay 50,

series avithrelayw, one-na ycircuitextending from ground, tlir-oughthe right-handnor `malcontacts of keyrOVcontacts `ofliey 167,.

contacts 6.8 ot dialO, windings of-relays 11,112 .and 10 and .lett-hand normal contacts otkcy (iO-to groundedbattery. Polarized relay 1Q.. does not. operate Iatthis time .since currentftlow is not inthe proper direction.'V

Ajcircuitiszthen completedi'orirelay .5,0 oi" theconnector `switch TG over. a. path extend-- ing from kgrounded battery, through :the Winding .ot relay 50,; terminal .47, brush $3, contacts@ ot' relaya26,;lett,hand contacts of relay 28,fcontacts otrelay .l2 .and Lipper youter contacts 4ofrelayigll.to ground. Relay 50 operates in this circuit `and completes .an

obvious circuit tor .sloivzto release relay 51. .TWhen the testing operatordials the Vnext digt,'ctor example, N 0.12, relayllfunctons to .repeat the. impiilscsto line relay 50 ,of the.;

test connector TC. y.illaclrtimethe relay 1l deenergizes, theabove traced circuit for re-y the succeeding,` .impulse `ot the series, relay.

50 deenergizes .a correspondingnumber of times thereby transmitting4 impulsestov magnet 53,0vera path extending vfrom `around through thelnormal.contacts oit'relay 50,

alternate contacts ot' relay .51, contacts58-ot oil-normal switch 9.9,.alterna .te..contacts and 513 `to .grounded battery.' .In vresponse .to these impulses magneti 53 operates ,to move the .brushes oi" -theconnector .switchr T C a number of stepscorresponding-tothe imf pulses transmitted. Atterthecessation of switch TC in a rimani Vdirection rela s 11,50 andv lreinainenergized but relay 52 releases. Relay releases. dueto theopein ing of.' its circuit .Willen the testing' :operator dijals-tliene'xt digit, No. .5, :tor example,zth.e relay 111 will momentarily dcenergize iivetimes-and will send tive impulses of current .to .the relay 50,ivliich in turn Willftransmit live impulses of currentto the secondaryinagnet 5.5 over apath extending riircm groiindthrough the normal contactsorelay .50, alternate contacts oixrfelay 51, contacts 58V of the off-normal. switch 99.', lnormalcontacts. of `relay 52 for moving the :connector at` .the vnormal contactsv andavinding of magnet 5.5 to grounded'battery. .The secondary ,magnet 55 will be operated. overthis circuitandwill move the brushes .74, 7.5 and V7.6 .of the connector switch TC into cngagementwitli .the :terminals oi' the :line corresponding .to y.the number ot' impulses transmitted.

During the transmission voil `the impulses, 'for rsetting the test connecter, relay. 10 Vis intermittently deenergized... Attlie lirst interruption of the circuit of relay .1.0 inresponse tothe transmission oi' .theiinpulses `tor .moving the. connector sWitchTC in its primary movement, .relay 29 is operated f over .a `circuit extending ftromugrounded, :hat-y tery, thronghthe lower winding otrelay 2.9, normal contacts of magnetl, outer righthand normal contacts of relay 28, normal contacts of relay let, contacts 19 oit ott-norn mal .switch 22, lower .alternate contacts ot.

relay 13, lower normal contacts ot relay .1l and .normal contacts. of. relay Il() to. ground. The same circuit is completed for relay 29 during,` `the .secondary movement .of .switch TC. Relay 29 operates in .thiscircuit and.

being of the sloW-to-release type, remains operated during the transmission ot the remaining.impulsesof a. series. .Relay Q9 in operating disconnects the talking conductors of the connector from the test kdesk dur`l ing. the time that theibrushes of the -connector are moving. over its associated contacts.

Ifthe Vline selected Vis busy,ground -Will be present uponits testterminal 96 in the vconnectorswitch TC dueitoa .ground con-` nectionapplied to. one oft its multiples by'a regular connector, and relay 29 will remain operated, when dialing. ceases, over a path extending from i ground at terminal 96,

through brush .76, terminal 16, brush ft2, upper normal contacts of .relay 98 and upper Winding ofrelay) .topgrounded battery. When thedialreturns tonormal and contactl.closesatterthe last digit has been dialedylamp 32 Willbeiiashed 'due to the intermittent operation of relayl) over` th path previously. traced. rllie 'flashing ot this signal indicates tothe testing operator that the .selected line .isp busy.

. .It thetestingoperator desires to connect .to the `called line .mits busy condition. he

will open keycontacts 67 thereby opening the. short. circuit extending. through contacts 67 Yaround the high resistance G2. Theiin:

withV relaysll land A21.0 causes thereleaseot relay l0.V vRelay vllfremains operated hon'- ever.- VRelay l0, .in releasing, completes a circiiit .orrelay 9810ver a path enteiiding 'from .-ground, .through f the normal contacts of relay f1.0,lower alternatecontacts ofre- 'layll and winding` o'frelay 98 togrounded battery. Relay 98, .inl operating,` opens .the

energizing; circuit torn relay 29A extending to lli) viso 'seition ofthe l-iig'h resistance 62 in series ground at the test terminal 9G. The testing operator may then actuate key l5-thereby extending the test circ-uit 90, 91 through the upper and lower alternate contacts et key to the selected line.

if the selected line is idle, relay 29 will release as soon as the operator completes dialing. Relay 30 will then be operated over a path extending from ground, through the left-hand winding ot the line relay 9T of the called station, terminal 941,'brush 74;, terminal lei, brush it), upper noi'mal contacts of relay 2S), conductor Si, upper normal contacts ot key winding ot' relay 30, lower normal contacts ot key 35, conductor 85, inner normal contacts ot relay 2S), brush Ll1, terminal Ll5, brush 75, terminal 95 and righthand winding ot' relay 9T to grounded battery. It the selected line is in a normal condition, relay 30, will operate, causing lamp to glow steadily over the circuit previously traced. Relay 9T does not operate at this time due to the high resistance ot relay 30 in series with it. It, however. the selected line is not in a normal condition, relay 230 will not be operated and lamp 32 will not light.

1f the tester so desires lie can advance the test connector across the selected level, one step at a time, by simply dialingl to send impulses suliicient to step the brushes to the wanted line, tor example, it alter having established a connection with the station D, whose number has been assumed to be 34:25, the testing operator desires to establish a connection with the subscriber whose number is SL12, he will simply dial the digit 2 which. will advance the test connector TC two steps in a secondary movement thereby establishing connection with the subscriber in the station whose number is 3427.

it the test operator desires to test a line which is reached by the same test connector but in a dili'erent group, he may release the test connector without releasing the test distributor by operating the reverse battery key GO which will cause the polarized relay 12 to operate to elifect the release ot the test connector. Actuation of key 60 causes the current to low through polarized relay 12 in the reverse direction whei'eupon relay 12 attracts its armature thereby opening the circuit ttor relay ot the test connector TC. Relay 50, in releasing, releases relay 51 thereby completingl a circuit 'for release magnet 54s of the test connector TC over a path extending from ground through the normal contacts of relay 50, normal contacts of relay 51, oli-normal contacts 5G and winding ot magnet 551. to grounded battery. Magnet 54: operates in this circuit and causes the restoration of the switch TC to normal in the manner well known in the art. The testing operator may now restore key to normal and then dial the two digits necessary to step the connector on to the desired line. rllhe operation of the connector is, in this instance, similar to that previously described.

After the testing operator has completed the tests he may open contacts SO to 83, inclusive. rllhe openingof contacts 82 and 83 causes the release of relays 11 and 10. Relay 11, in releasing, opens the circuit igor the slow-to-release relay 13 of the switch Tl) and relay 50 of the test connector TC. Relay 50 in releasing causes the release of relay 51 and the operation of release magnet 54C. Magnet 51, in operating, restores the connector switch TC to normal. The release ol relays 10, 11 and 13 completes a circuit for the release magnet 15 or the test distributor over a path extending from ground, through the normal contacts ot relay 10, lower normal contacts of relay 11, lower normal contacts oi" relay 13, oit-normal contacts (55, and winding oi release magnet 15 to grounded battery. Magnet 15 operates in this circuit and causes the restoration of test distributor switch TD to normal in the manner well known in the art. The circuits are now in condition tor use again.

The testing equipment of the operators position connected to conductors 90, 91, is not shown since it forms no part of this invention. lt may be of the type shown and described in Smith and Campbells book entitled Autoniatic Telephony, (second edition) pp. 36? to lhat is claimed is:

1. ln a testing system, a switch, a set ot terminals therein, means lor positioning the switch brushes on said terminals whether idle or busy, another switch reached by the switch iirst mentioned via said terminals, a test circuit including one of said brushes and one of said terminals, and an impulse circuit including said brush and terminal for setting the secondly mentioned switch.

In a testing system, a plurality of test distributors, a plurality of test connectors terminating in fixed sets of terminals in said test distributors, means 'for positioning the brushes of a test distributor on the iixcd set ot terminals leading to a given test connector, a test circuit including one oi" said brushes and one oit said terminals, a circuit for guarding said connector including said bi'ush and terminal, and an impulse circuit for setting said selected connector also including said brush and terminal.

1n a testing system, a plurality ot test distributors, a plurality or test connectors terminating in lixed sets of terminals in said test distributors, means for positioningthe brushes oit a test distributor on the. fixed set of terminalsfleading to a given test connector, a test circuit including one of said brushes and one ot said terminals, a circuit for guarding said connector including said brush and terminal, an impulse circuit for terminating in fixed sets ofl terminals in test distributors, means for positioning the brushes of a test distributor on the'fixed'set of terminals leading to a given'test connector, a test circuit including one of said brushes and one of said terminals, a circuit for guarding said connector including` said brush and terminal, an impulse circuit for setting said connector, a release circuit Jfor said connector including said brush and terminal, manually controlled means for opening said circuit to release said connector, a release circuit for said distributor, and manually controlled means circuits of both the distributor and connec-k tor( 5. In a testing system,a first switch, a second switch, means for setting the first switch on a set of terminals leading to the second switch whether idle or busy, means at the first switch for .testing `the second switch, means for transmitting impulses to the second switch, anda common conductor over which said testing means is actuated and said impulses are transmitted.

6. In a testing system,ra first switch having a plurality of brushes, a second switch, testing devices at said first switch, impulse repeating means at saidv first switch, means for setting the brushes of said first switch on the terminals leading to said second switch whether idle or busy, and a circuit comprising one brush of said first switch for connecting said testing devices and said impulse repeating means in operative relation ship with said second switch.

7. In a testing system, a subscribers line,

an impulse sender, a first switch having a plurality of' movable contacts, a second switch, means controlled by said sender Jfor for closing the release connecting said first switch to said second switch'whether idle or busy, a repeating relay at said first switch for controlling the setting of' said second switch, a test circuit including one of the movable contacts of said first switch for testing said second switch for a busy or idle condition, and means operative if' the second switch is idle for connecting the repeating relay in operative relationship with the second switch over the movable contact included in the test circuit.

8. Ina testing system, a subscribers line, a first switch comprising a pair of talking conductors and a pair of non-talking conductors, a second switch, testing devices at said first switch, impulses repeating means at said first switch, a circuit including one of the non-talking conductors of' said first switch for connecting one of said testing devices andsaid impulse repeating means in operative relationship with said Second switch, and a circuit including the other .of said non-talking conductors of said selector switch for placing said other testing devices .in operative relationship with'` said subscribers line.

9. In a testing system, an operators position, a subscribers line, -a train of automatic switches, a circuit extending between said position andy said switches, means for setting said switches in sequence over `said circuit whereby said position is llinked `to said line, means for indicating to the operator that the line is busy, and means at the first switch of the train actuated over the said circuit in response to a control exercisedV by the operator upon receiving the busy signal for enabling lier to establish a connection with the line when it is busy.

In witness whereof, I hereunto subscribe my name this 15th day of' December A. D., 1922.

RAY L. STOKELY. 

